CHAPTER IX 



LEARNING AMONG THE HIGHER ANIMALS. THE METHOD 

 OF TRIAL AND ERROR 



WE have now to ask whether there is any evidence that 

 this stage of intelligence is attained by any animals other 

 than man. 



i . Let us begin by considering a very simple instance of 

 the apparently purposive choice of means to an end. I 

 once had a cat which learnt to " knock at the door " by 

 lifting the mat outside and letting it fall. 1 The common 

 account of this proceeding would be that the cat did it in 

 order to get in. It assumes the cat's action to be 

 determined by its end. Is the common account wrong ? 

 Let us test it by trying explanations founded on the more 

 primitive operations of experience. First, then, can we 

 explain the cat's action by the association of ideas ? The 

 obvious difficulty here is to find the idea or perception 

 which sets the process going. The sight of a door or a 

 mat was not, so far as I am aware, associated in the cat's 

 experience with the action which it performed until it had 

 performed it. If there were association, it must be said to 

 work retrogressively. The cat associates the idea of getting 

 in with that of someone coming to the door, and this again 

 with the making of a sound to attract attention, and so 

 forth. Those who hold language of this kind are really 

 describing what I have called the Practical Judgment in 

 different terms. Such a series of associations so well 

 adjusted means in reality a set of related elements grasped 



1 The habit is, I believe, not uncommon among cats. 

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